With the rapid development of LED technology, its luminous efficiency has gradually increased, and the LED application market has become more extensive. Especially in the context of the global energy shortage worry, the prospect of LED in the lighting market has attracted worldwide attention. The gradual maturity of intelligent lighting technology has enabled more and more companies to intervene in this field. Major companies have made their own dimming fixtures, and the schemes used are various.
FIG. 1 shows the traditional lamp dimming circuit used in most enterprises. The traditional lamp dimming circuit mainly includes power module, dimming controller, microcontroller, dimmer and LED lamp. The power module, dimming controller and the microcontroller will have a grounding point correspondingly; the power module is span connected to the dimming controller through a Y capacitor, and another Y capacitor is also disposed between the dimming controller and the microcontroller, and the microcontroller is connected with the dimmer, and the dimming controller is connected to the LED light. Thus, part of the common mode interference is eliminated by the Y capacitor span connecting between the power module and the dimming controller, the dimming controller and the microcontroller. At the same time, the electricity leakage current of the Y capacitor flows through the three grounding points. If the number of interconnected lamps increases, a large electricity leakage current will flow through the dimming circuit of the lamp dimming circuit, which may cause electric shock.